25 OH Vitamin D

A Gerstel Multi Purpose Sampler coupled with liquid chromatography and electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS) for the determination of 25 OH vitamin D2 and D3
Clinical details: 
Vitamin D is converted into 25-OH vitamin D in the liver. This is the major storage form of vitamin D and is the analyte of choice for determination of the vitamin D status. Hypocalcaemia can result from vitamin D deficiency or disorders of vitamin D metabolism such as renal failure. Hyper and hypo-phosphataemia can each be caused by vitamin D excess and deficiency respectively.
Vitamin D deficiency prevents normal absorption of calcium from the gut leading to increased mobilisation of calcium from the bone in order to maintain blood concentrations. The resulting demineralisation of bone leads to bone weakness known as rickets in children, or osteomalacia in adults. Vitamin D deficiency can occur secondary to various diseases that cause fat malabsorption. These include cystic fibrosis, primary biliary cirrhosis, short bowel syndrome, pancreatic disease and Crohn’s disease. Vitamin D toxicity is due to over-consumption of supplements and cannot be caused by excess exposure to sunlight.
Reference range: 

<25 nmol/L     – vitamin D deficiency

25-50 nmol/L  – vitamin D insufficiency

>50 nmol/L    – good vitamin D status

Synonyms or keywords: 
cholecalciferol, ergocalciferol, vitamin D2 and D3
Sample type and Volume required: 
Call in advance: 
Turnaround time: 
10 days
Nutristasis Unit at St Thomas'
020 7188 6815 / 89543
St Thomas' Hospital
North Wing - 4th Floor
Westminster Bridge Road
London SE1 7EH

Laboratory opening times
Monday - Friday 09.00 - 17.00
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 22/01/2021